What two factors make it difficult to enter a market ?

Product differentiation

Existing firms have officials identification of the goods brand and consumer loyalties. Therefore it is difficult for a new firm to entire a market with a new brand and to gain customer loyalty.

Capital Requirements

The financial resources needed for the foundation, machinations, Research and Development, latest Technology and Promotion of the brand of a market. Capital Requirement is also a factor that could make it difficult for new firms to enter a market.  

what is the other part to the question

c- companies fail to take environmental protection into account. i think